Loud-speaker unit



E; F. HOLINGER LOUD SPEAKER UNIT Dec. 20, 1927.

Filed Sept. 4. 1926 mvgmoa .101: rage 2 ATTORNE Patented Dec. 20, 1927.

UNITED STATES 1,653,045 PATENT OFFICE;

EMIL F. HOLINGER, OF NEW YORK, N. Y., ASSIGNOB OF ONE-HALF TO E. CHASE I CROWLEY, OF NEW YORK, N. Y.

LOUD-SPEAKER 1mm.

Application filed September 4, 1928. Serial No. 138.581.

cated. The best iormof a'ppa'ratus at pres- 'ent known to me embodyingmy invention is illustrated in the accompanying sheet of drawings in which,

F ig; 1 a vertical,'central sectioh of the ap ara'tus, and

ig. 2 is a line 2-2 of Fi 1.

Throughout fihe drawings like reference characters indicate like parts. 1 is any suit-- able base, 2 a su porting member therein to which is fasten the core piece 3 of a mag net and the lower end of a vertical rod 4. vThis rod preferably is tubular, as shown, and at its up r end carries an internally threaded mem r 6 which sup orts the thinwalledhollow sphere-6 ma 0 of resonant material such as indurated fibre, hardrubher or other suitable constituents forming a substantially closed air chamber. 9 is a lock nut for holding member 5 in any position of adjustment; Rod 4 Ipasses through an opening 7 at the lower p0 e of the sphere but is not in contact withit at that point, the member 6 being supported only at its horizontal section taken on upper pole and hanging free from that point. p

8 is an armature, which may be annular in form, attached to sphere 6 adjacent to 0 ning 7 and thereby supported in the field o the electr.0 ma et formed'bycoils 10, 10, wound on core 171806 3, the terminals 11, 11 of which coils may be connected in circuit with the receivi set. Supportin member 2 may be remova ly mounted in use 1 by screws 12, 12.

In operation the impressed magnet impulses cause vibrations inarmature 8 which are transmitted to sphere'6 and reproduced in the air, both inside and outside of sphere, giving forth clear and accurate duplications of the original sounds impressed on the microphone of the usual sending or broadcastin apparatus with which the receiving set ism tune.. The sound waves in the interior of sphere 6 escape through opening 7 to mingle with and reinforce those gener- '-ated-on its exterior. and I believe that the excellentquality of the reproduction -is due, in part at least, to the fact that, as the memher 6 is integral in character. and uniform in curvature, and convexity, these two sets of sound waves differ only slightli in phase, one from thcother, justsutlicicntly to bring out-the overtones, but not sufiicicntly to produce any blurring or confusion by the combination.

Obviously various changes could be made in the relative arrangement and special construction of the constituent elements herein described and illustrated without departing from the principle of operation disclosed or entirelylosing the advantages of my invention.

Having described my invention, I claim:

1. A loud speaker unit for sound reproducing having, in combination, a hollow, thin-walled spheroidal member of resonant material forming a substantially closed air electro-magnet within the field of which said armature is located.

2. A combination such as defined in claim 1 in which said resonant member 18 8. here with the opening at its lower pole, an said support comprises a vertical rod passing through said opening.

' 3. A combination such as defined in claim 1 in which said resonant member is a here, with the opening at its lower pole, an said support comprises a vertical rod pass' through said opening and provided with an adjustable, screw-threaded connection to the upper pole of sphere.

4. A combination such as defined in claim 1 in which said resonant member is a here, with the opening at its lower pole. an said support comprises a' vertical rod passing through said opening and provided with an adjustable, screw-threaded connection to the upper pole of sphere and a base member in which the lower end of said rod and said clcctro-magnet are fastened exteriorly of said sphere.-

EMIL F. HOLINGER. 

